@article{GDZPPN00204112X, title = {D'Alembert's equation and spherical functions.}, journal = {Aequationes mathematicae}, volume = {47}, year = {1994}, pages = {220-227}, zbl = {0810.39008}, url = {http://dml.mathdoc.fr/item/GDZPPN00204112X} }
Stetkaer, Henrik. D'Alembert's equation and spherical functions.. Aequationes mathematicae, Tome 47 (1994) pp. 220-227. http://gdmltest.u-ga.fr/item/GDZPPN00204112X/